(1) Field of the Invention
The present invention relates to a laminated board suitably used for printed circuit boards used in electric apparatuses, electronic apparatuses, communication apparatuses, etc.; as well as to a process for production of the laminated board.
(2) Related Art Statement
With the advance of home-use electronic apparatuses into smaller sizes and higher performances, there have come to be used, as printed circuit basic materials used therein, laminated boards obtained by impregnating a nonwoven glass fiber fabric (as a substrate for intermediate layer) and a woven glass fiber fabric (as a substrate for surface layers) with an epoxy resin and subjecting the resulting fabrics to hot pressing (the laminated boards are hereinafter referred to as "composite laminated board"). Recently, it has become necessary that these composite laminated boards possess (1) punchability comparable to that of laminated boards comprising a paper substrate and a phenolic resin, heretofore used in the art and (2) a low cost.
Also in industrial-use electronic apparatuses, composite laminated boards have come to be used in which no woven glass fiber fabric is used or the amount thereof is decreased for cost reduction. These laminated boards, however, are inferior to laminated boards using a woven glass fiber fabric as a substrate, in various performance respects, and it has become necessary that they show a small dimensional change and a small warpage both comparable to those of the latter boards.